1. Field of the Invention
This invention relates to an improvement in an apparatus for delivering liquids under pressure generated by an elastomeric bladder. More particularly, it relates to an improvement in the elastomeric bladder of such an apparatus.
2. Description of the Prior Art
It is well known that when a liquid is pressured into an elastic container so as to distend the container walls, these elastic walls apply pressure to the liquid. This pressure may be used to propel the liquid out of the container. This relationship finds embodiment in such diverse items as water balloons, pressure accumulators (see U.S. Pat. No. 2,480,558, issued Aug. 30, 1949 to DeKiss), sprayers (see U.S. Pat. No. 3,083,871, issued Apr. 2, 1963 to Jepson), pressure pack barrels (see U.S. Pat. No. 2,816,590, issued Dec. 17, 1957 to Lari), intravenous infusion devices (see U.S. Pat. No. 3,486,539, issued Dec. 30, 1969 to Jacuzzi, and U.S. Pat. No. 3,469,578, issued Sept. 30, 1967 to Bierman), and non-aerosol dispensers (see U.S. Pat. No. 3,791,557, issued Feb. 12, 1974 to Venus, Jr.). All of these fluid delivery devices share the same basic structure. Each has a distensible elastic bag or bladder which applies pressure to an enclosed liquid and forces this liquid through a valve which modulates the rate of flow of liquid from the bladder.
Many of these devices function suitably in very crude forms. In other cases it is necessary that the devices be refined to provide an accurately controlled flow of liquid. The present invention relates to an improved elastic bladder for use in fluid delivery devices of the type described hereinabove. The bladder of this invention gives better liquid discharge characteristics than bladders employed heretofore and would find primary application in those devices where precise control of fluid flow is an object.